STLLR Gold’s Hollinger Tailings Project Maiden Mineral Resource Estimate Provides A Strong Foundation for Exploring Future Short-Term Development Under Ontario’s New Recovery of Minerals Regime
Press Release
TORONTO, Ontario, November 25, 2025 – STLLR Gold Inc. (TSX: STLR) (OTCQX: STLRF) (FSE: O9D) (“STLLR” or the “Company”) is pleased to announce the results of a maiden Mineral Resource Estimate (“MRE”) for its Hollinger Tailings Project (“Hollinger”) located in the Timmins Mining Camp in Ontario, Canada.
Keyvan Salehi, P.Eng., MBA, President, CEO and Director of STLLR, stated, “The maiden Hollinger MRE marks a significant de-risking milestone since the genesis of STLLR Gold and a big step towards remediating a 100-year-old site. Hollinger has rapidly emerged as one of the most exciting near-surface gold opportunities in the Timmins Mining Camp. In under twelve months, we progressed from initial access to delivering a robust tailings MRE with more than 82% of the mineralization in the Indicated category. Overall, Hollinger has now been characterized with a high level of confidence and consistency, which is the start of us mapping out a path to potential cash flows at current gold prices.”
“The hallmark of Hollinger is its uniformity. Hole after hole demonstrates remarkably consistent gold grades across the facility. Based on the geological continuity observed, we believe there is clear potential to add meaningful ounces, particularly along the northwest and northeast corners that could not be drilled last season.”
“Phase 1, which hosts the higher average estimated grades of 0.41 g/t Au in the Indicated mineral resource category, presents a compelling early opportunity for value creation. Our technical teams are advancing mining sequence analysis and operating scenarios specifically tailored to Phase 1, with the goal of positioning this portion of the deposit as the logical starting point for any future potential production plan.”
“From a business standpoint, we continue to explore how Hollinger stands out to generate near-term cash flow at current gold prices with minimal capital intensity given the surrounding infrastructure. As a result of the near-surface material having been previously mined and with strong metallurgical recoveries for tailings material, we believe that Hollinger represents a rare opportunity to unlock value without the long timelines and major capital typically associated with conventional greenfield mining projects.”
“Equally important is the permitting pathway. We have initiated permitting under Ontario’s new Recovery of Minerals Regime, which was specifically designed to streamline the development of such projects. Our experience with the Ministry of Energy and Mines over the past year — support for the characterization program and rapid collaborative engagement — gives us confidence in the process ahead.”
“I am extremely proud of the team. Securing access, establishing a strong working relationship with the Ministry and the City of Timmins, completing the significant sonic characterization program, advancing metallurgical work, and now delivering an NI 43-101 MRE — all in under a year — is a testament to the efficiency and discipline of our organization and demonstrates what is possible when the geology, permitting pathway, and execution all align.”
“We believe Hollinger has the potential to deliver value on multiple fronts: environmental rehabilitation by reprocessing a century-old tailings facility, community benefit by unlocking long-term surface land use opportunities, and meaningful near-term value creation for shareholders. We remain committed to working collaboratively to advance the project through the permitting process in 2026. Hollinger represents a rare opportunity: near-surface mineral resource ounces under a permitting regime specifically designed to accelerate recovery of minerals from historical tailings.”
Michelle Boileau, Mayor of Timmins, Ontario, commented, “The City of Timmins’ continued collaboration with STLLR Gold is a powerful example of how modern mining can be a force for sustainable development. By reprocessing historic mine tailings, the Hollinger Tailings Project has the potential to remediate the environment and unlock new land-use possibilities in the City of Timmins.”
Table 1: Hollinger MRE Summary[1] (Effective date of November 24, 2025). Please review “Notes to Accompany the Hollinger MRE” for additional information. [1] Please review the “Cautionary Statement regarding Mineral Resource Estimates” at the end of the news release.
There is no certainty that the Hollinger MRE will be converted to Proven and Probable Mineral Reserve categories or will be realized in the future. Mineral Resource estimates that are not Mineral Reserves do not have demonstrated economic viability. The Hollinger MRE may be materially affected by environmental, permitting, legal, title, taxation, socio-political, marketing, access to processing facilities, or other relevant risks, uncertainties and other factors, as more particularly described in the Cautionary Statements at the end of this news release.
Notes to Accompany the Hollinger MRE
(1) These mineral resources are not mineral reserves as they do not have demonstrated economic viability. The Hollinger MRE follows current CIM Definition Standards (2014) and CIM MRMR Best Practice Guidelines (2019). The resource estimate is presented as in-situ and undiluted and is considered to have reasonable prospects for eventual economic extraction.
(2) The mineral resources are constrained by a resource pit shell based on a 0.21 g/t Au cut-off representing a truck and loader extraction scenario. The cut-off grade of 0.21 g/t Au was calculated using the following parameters: operating cost = CA$17.00/t; payable gold = 99.95%; gold price = US$3,000/oz; USD/CAD exchange rate = 1.38; mill recovery of 61.3%.
(3) The independent and qualified person for the Hollinger MRE, as defined by National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43‑101”), is Brian Thomas, P.Geo. of WSP Canada Inc. (“WSP”). The effective date of the MRE is November 24, 2025.
(4) The estimation encompasses wireframes representing Phase 1 and Phase 2 walls and cells which contain the tailings material.
(5) High-grade capping of assays was set at 1.3 g/t Au.
(6) The estimate was completed with a sub-blocked model in Datamine Studio RM, with a parent block size of 10 m x 10 m x 1 m (X,Y,Z) and a minimum sub-block size of 2.5 m x 2.5 m x 0.5 m (X,Y,Z), using inverse distance squared (ID2) interpolation method based on 1m composite samples.
(7) Density values for tailings material ranged between 1.6 g/cm3 and 1.9 g/cm3 according to depth and differences between material in walls and cells.
(8) Hollinger Mineral Resources were classified as Indicated and Inferred. Indicated mineral resources were defined for blocks where drill hole spacing is 50 m or less and Inferred mineral resources where drill hole spacing is greater than 50 m.
(9) Potential mining continuity was evaluated inside the pit shell by generating grade shells. Grade shells below cut-off within the resource pit shell with volumes greater than 2,500 m3 were assumed to be sortable and were excluded from the MRE. Grade shells below cut-off with volumes less than 2,500 m3 were assumed to be too small for sorting and included in the MRE.
(10) The resource tonnage was rounded to the nearest 100,000 tonnes and the metal contents are presented in troy ounces (tonnes x grade / 31.10348) rounded to the nearest thousand ounces. Any discrepancies in the totals are due to rounding effects.
(11) The Hollinger MRE is based on a 61.3% gold recovery rate via cyanide leaching at a 30-micron grid size. The Company also tested flotation at a 38-micron grind size and achieved 82.5% gold recovery with a 11.7% mass pull and grading 2.69 g/t Au, 2.3 g/t Ag and 16.5% sulfur.
(12) As of the effective date of the MRE, the qualified person is not aware of any known environmental, permitting, legal, title-related, taxation, socio-political, or marketing issues or any other relevant issue that could materially affect the Hollinger MRE.
Mineral Resource Estimate and Metallurgical Testing
The Hollinger MRE (see Table 1 and Figure 1) is based on 11,230 metres (“m”) of characterization sonic drilling from 423 holes spaced on a 50 m grid, successfully classifying 82% of the mineralization in the Indicated mineral resource category. The Hollinger Tailings stack on average covers an area 1,950 m long, 1,250 m wide and up to 40 m thick in the southwest corner. The geological and mineralization domain models were developed based on depositional history, lithological logging and assays results, confirming strong continuity and consistency in mineralization and grade in the tailings.
The design of the metallurgical program and review of the results was completed by WSP and analysis was performed by SGS Canada Inc. Initial results show 61.3% gold recovery via conventional cyanide leaching, a common configuration of the processing facilities proximal to Hollinger with excess capacity. The Company sees an opportunity to improve recovery with further testing.
Figure 1: Hollinger MRE – Block Model Plan View
Permitting
STLLR has begun permitting under Ontario’s new Recovery of Minerals regime, which streamline recovery permits for residual minerals from tailings without requiring a full closure plan. The Company expects an expedited timeline and will provide updates as information becomes available.
Technical Report and Qualified Persons
A Technical Report prepared in accordance with NI 43-101 in support of the MRE (“Technical Report”) will be filed on SEDAR+ (www.sedarplus.ca) within 45 days. Readers are encouraged to read the Technical Report in its entirety, including all qualifications, assumptions and exclusions that relate to the MRE. The Technical Report is intended to be read as a whole, and sections should not be read or relied upon out of context.
Scientific and technical information related to the MRE contained in this news release has been reviewed and verified by Brian Thomas, P.Geo. of WSP a “Qualified Person” (“QP”) as defined by NI 43-101. This person has the ability and authority to verify the authenticity and validity of this data and is independent from the Company.
John McBride, MSc., P.Geo., VP Exploration, is a QP as defined by NI 43-101 for Hollinger, has reviewed and approved of the scientific and technical disclosure contained in this news release.
About STLLR Gold
STLLR Gold Inc. (TSX: STLR; OTCQX: STLRF; FSE: O9D) is a Canadian gold development company actively advancing high-potential gold projects in Canada: The Tower Gold Project and the Hollinger Tailings Project in the Timmins Mining Camp in Ontario and the Colomac Gold Project located north of Yellowknife, Northwest Territories. Tower and Colomac have the potential to become large-scale, long-life operations and are surrounded by exploration land with favourable upside potential. Hollinger has the potential for near-term value creation. STLLR’s experienced management team, with a track record of successfully advancing projects and operating mines, is working towards rapidly advancing these projects.
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